tests/driver_dac_dds: Parametrize configured DAC device
tests/driver_dac_dds: Parametrize configured DAC device

The set default is good enough for single-channel board, but whenever
DAC_DDS_CHAN is not zero (or even when a board has more), this may need
changing.

jasonatran/RIOT,kYc0o/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,OTAkeys/RIOT,kaspar030/RIOT,kaspar030/RIOT,kYc0o/RIOT,ant9000/RIOT,kaspar030/RIOT,OTAkeys/RIOT,miri64/RIOT,miri64/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,authmillenon/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,ant9000/RIOT,ant9000/RIOT,authmillenon/RIOT,miri64/RIOT,kYc0o/RIOT,kYc0o/RIOT,miri64/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,kaspar030/RIOT,ant9000/RIOT,ant9000/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,jasonatran/RIOT,jasonatran/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,OTAkeys/RIOT,kaspar030/RIOT,authmillenon/RIOT,OlegHahm/RIOT,authmillenon/RIOT,jasonatran/RIOT,jasonatran/RIOT,OTAkeys/RIOT,miri64/RIOT